<template>
  <div class="q-pa-md">
    <div class="text-subtitle1 q-pa-sm"
      >Use <kbd>SHIFT</kbd> to select / deselect a range and <kbd>CTRL</kbd> to
      add to selection</div
    >

    <t-table
      flat
      bordered
      ref="tableRef"
      title="Treats"
      :rows="rows"
      :columns="columns"
      row-key="name"
      selection="multiple"
      v-model:selected="selected"
      @selection="handleSelection"
    >
      <template v-slot:header-selection="scope">
        <t-checkbox v-model="scope.selected" />
      </template>

      <template v-slot:body-selection="scope">
        <t-checkbox
          :model-value="scope.selected"
          @update:model-value="
            (val, evt) => {
              Object.getOwnPropertyDescriptor(scope, 'selected').set(val, evt);
            }
          "
        />
      </template>
    </t-table>
  </div>
</template>

<script>
  import { nextTick, ref, toRaw } from 'vue';

  const columns = [
    {
      name: 'name',
      required: true,
      label: 'Dessert (100g serving)',
      align: 'left',
      field: row => row.name,
      format: val => `${val}`,
      sortable: true,
    },
    {
      name: 'calories',
      align: 'center',
      label: 'Calories',
      field: 'calories',
      sortable: true,
    },
    { name: 'fat', label: 'Fat (g)', field: 'fat', sortable: true },
    { name: 'carbs', label: 'Carbs (g)', field: 'carbs' },
    { name: 'protein', label: 'Protein (g)', field: 'protein' },
    { name: 'sodium', label: 'Sodium (mg)', field: 'sodium' },
    {
      name: 'calcium',
      label: 'Calcium (%)',
      field: 'calcium',
      sortable: true,
      sort: (a, b) => parseInt(a, 10) - parseInt(b, 10),
    },
    {
      name: 'iron',
      label: 'Iron (%)',
      field: 'iron',
      sortable: true,
      sort: (a, b) => parseInt(a, 10) - parseInt(b, 10),
    },
  ];

  const rows = [
    {
      name: 'Frozen Yogurt',
      calories: 159,
      fat: 6.0,
      carbs: 24,
      protein: 4.0,
      sodium: 87,
      calcium: '14%',
      iron: '1%',
    },
    {
      name: 'Ice cream sandwich',
      calories: 237,
      fat: 9.0,
      carbs: 37,
      protein: 4.3,
      sodium: 129,
      calcium: '8%',
      iron: '1%',
    },
    {
      name: 'Eclair',
      calories: 262,
      fat: 16.0,
      carbs: 23,
      protein: 6.0,
      sodium: 337,
      calcium: '6%',
      iron: '7%',
    },
    {
      name: 'Cupcake',
      calories: 305,
      fat: 3.7,
      carbs: 67,
      protein: 4.3,
      sodium: 413,
      calcium: '3%',
      iron: '8%',
    },
    {
      name: 'Gingerbread',
      calories: 356,
      fat: 16.0,
      carbs: 49,
      protein: 3.9,
      sodium: 327,
      calcium: '7%',
      iron: '16%',
    },
    {
      name: 'Jelly bean',
      calories: 375,
      fat: 0.0,
      carbs: 94,
      protein: 0.0,
      sodium: 50,
      calcium: '0%',
      iron: '0%',
    },
    {
      name: 'Lollipop',
      calories: 392,
      fat: 0.2,
      carbs: 98,
      protein: 0,
      sodium: 38,
      calcium: '0%',
      iron: '2%',
    },
    {
      name: 'Honeycomb',
      calories: 408,
      fat: 3.2,
      carbs: 87,
      protein: 6.5,
      sodium: 562,
      calcium: '0%',
      iron: '45%',
    },
    {
      name: 'Donut',
      calories: 452,
      fat: 25.0,
      carbs: 51,
      protein: 4.9,
      sodium: 326,
      calcium: '2%',
      iron: '22%',
    },
    {
      name: 'KitKat',
      calories: 518,
      fat: 26.0,
      carbs: 65,
      protein: 7,
      sodium: 54,
      calcium: '12%',
      iron: '6%',
    },
  ];

  export default {
    setup() {
      const tableRef = ref();
      const selected = ref([]);
      let storedSelectedRow;

      return {
        tableRef,
        selected,
        columns,
        rows,

        handleSelection({ rows, added, evt }) {
          // ignore selection change from header of not from a direct click event
          if (rows.length !== 1 || evt === void 0) {
            return;
          }

          const oldSelectedRow = storedSelectedRow;
          const [newSelectedRow] = rows;
          const { ctrlKey, shiftKey } = evt;

          if (shiftKey !== true) {
            storedSelectedRow = newSelectedRow;
          }

          // wait for the default selection to be performed
          nextTick(() => {
            if (shiftKey === true) {
              const tableRows = tableRef.value.filteredSortedRows;
              let firstIndex = tableRows.indexOf(oldSelectedRow);
              let lastIndex = tableRows.indexOf(newSelectedRow);

              if (firstIndex < 0) {
                firstIndex = 0;
              }

              if (firstIndex > lastIndex) {
                [firstIndex, lastIndex] = [lastIndex, firstIndex];
              }

              const rangeRows = tableRows.slice(firstIndex, lastIndex + 1);
              // we need the original row object so we can match them against the rows in range
              const selectedRows = selected.value.map(toRaw);

              selected.value =
                added === true
                  ? selectedRows.concat(
                      rangeRows.filter(
                        row => selectedRows.includes(row) === false,
                      ),
                    )
                  : selectedRows.filter(
                      row => rangeRows.includes(row) === false,
                    );
            } else if (ctrlKey !== true && added === true) {
              selected.value = [newSelectedRow];
            }
          });
        },
      };
    },
  };
</script>
